Bacterial infections instigated by antibiotic-resistant bacteria are considered perilous health threats in today’s world due to their fast-increasing nature and the fewer availability of new treatment strategies. The properties of nanomaterials triggered by external stimuli are considered an encouraging technique for the remediation of antibacterial infectious diseases by producing photoinduced reactive oxygen species (ROS). Light-mediated treatment using zinc oxide (ZnO)-based nanohybrids leads the field with high interest in terms of sensitization of antibiotics and their targeted delivery. Moreover, the dual sensitization in a hybrid system could produce more efficacy as this phenomenon has been implemented in dye sensitized solar cells and photocatalysis. However, most of those hybrids are complicated and non-biocompatible. The present study highlights a tri-hybrid by encapsulating tetracycline (TC) in Au nanoparticle-decorated ZnO nanoparticles. The composition and morphology of the samples were characterized by electron microscopy, ultrafast optical spectroscopy, and density functional theory-based techniques. The dual sensitization in the tri-hybrids leads to enhanced antimicrobial activity against Gram-positive Staphylococcus hominis bacteria due to immense ROS under white light irradiation. The Förster resonance energy transfer from TC to Au and the excited-state photo-electron transfer process in the Au_ZnO-TC tri-hybrid system trigger a huge charge separation, which enhances production of ROS. Due to such a huge ROS production capability, the tri-hybrid shows a significant antibacterial action. Moreover, the Au nanoparticle-decorated ZnO is capable of destroying excess antibiotics, which potentially reduces the chance of development of antibiotic resistance. Overall, the study demonstrates a promising aspect that could be beneficial for manifold biological applications.

Poly (viny1 alcohol) (PVA) was partially oxidized by alkaline KMnO 4 with an average carbonyl percentage of 65 %. PVA's photo physicochemical properties before and after the oxidation (OPVA) were investigated. The FTIR spectrum of OPVA revealed a new band at 1645 cm À 1 , corresponding to the carbonyl group and the XRD pattern reflecting an increase in the degree of crystallinity. Unlike pristine PVA, the UV-vis absorption spectra displayed the most attractive results through OPVA absorption in UV and visible regions. Further-more, the photoluminescence spectra of PVA membrane exhibited a narrow emission at 338 nm, whereas the OPVA membrane showed blue emission at 415 nm. The proton conductivity increased from 1.5 mScm À 1 in PVA to 11.1 mScm À 1 in OPVA at 70 °C. Thus, the presence of both hydroxyl and carbonyl groups in OPVA results in the formation of strong hydrogen bonding that facilitate proton transfers along the hydrogen-bond network.Density functional theory (DFT) investigation on PVA and OPVA oligomers confirmed that the oxidation induces a significant change on the frontier's orbitals, resulting in a decrease in the dipole moment (μ) and an electronic bandgap in the ground state. Indeed, the detected results for OPVA are promising for optoelectronic applications.

Herein, new substituted ligands based on pyrazole (L1–L4) were synthesized via a one-step by condensing (1H-pyrazole-1-yl) methanol with different primary amine compounds. The present work utilized the catalytic properties of the in situ complexes formed by these ligands with various copper (II) salts viz. Cu(CH3COO)2, CuSO4, CuCl2, and Cu(NO3)2 for the oxidation of catechol to o-quinone. The studies showed that the catalytic activities depend on the nature and concentration of the ligand, the nature of the counterion, and the solvent. It was observed that the complex formed by L2 and Cu(CH3COO)2 exhibited good catalytic activity in methanol with Vmax of 41.67 µmol L−1 min−1 and Km of 0.02 mol L−1.

In this work, we report on the catalytic activity of a manganese complex [(Cl)2Mn(RCOOET)], where RCOOET is ethyl-5-methyl-1-(((6-methyl-3-nitropyridin-2-yl)amino)methyl)-1H-pyrazole-3-carboxylate, in the oxidation of phenol or catechol by atmospheric oxygen to form o-quinone. The [(Cl)2Mn(RCOOET)] catalyzes the oxidation of catechol at a rate of 3.74 µmol L−1 min−1 in tetrahydrofuran (THF), in a similar manner to catecholase or tyrosinase.

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